President Donald Trump said Thursday the U.S. will impose new sanctions on North Korea over its nuclear weapons buildup, speaking just days after he threatened to "totally destroy" the country if forced to defend the U.S. or its allies.

The president placed the threat posed by North Korea at the center of his debut at this week's U.N. General Assembly, escalating his rhetoric against North Korea amid a monthslong crisis over Kim Jong Un's expanded missile testing program. National security adviser H.R. McMaster said Thursday the new measures would stop "short of war."

Trump was asked during a meeting on the sidelines of the United Nations about new punishments for the rogue nation and said new sanctions were coming. Details were to be announced later Thursday.

Vice President Mike Pence told Fox News Channel on Thursday: "We do not desire a military conflict. But the president has made it very clear, as he did at the U.N. this week, that all options are on the table and we are simply not going to tolerate a rogue regime in Pyongyang obtaining usable nuclear weapons that could be mounted on a ballistic missile and threaten the people of the United States or our allies."

Trump, in his Tuesday address to the U.N., said it was "far past time" for the world to confront Kim, declaring that the North Korean leader's pursuit of nuclear weapons poses a threat to "the entire world with an unthinkable loss of human life."

"Rocket Man is on a suicide mission for himself and his regime," Trump said, mocking the North Korean leader even as he sketched out potentially cataclysmic consequences. The president spoke of his own nation's "patience," but said that if "forced to defend itself or its allies, we will have no choice but to totally destroy North Korea."

The president was set to meet with and have lunch Thursday in New York with Japanese Prime Minister Shinzo Abe and South Korean President Moon Jae-in, who represent the nations most imperiled by North Korea's aggression.

Trump's overheated language was rare for a U.S. president at the rostrum of the United Nations, but the speech was textbook Trump, dividing the globe into friends and foes and taking unflinching aim at America's enemies. It drew a sharp rebuke from the North's Foreign Minister Ri Yong Ho, who said "It would be a dog's dream if he intended to scare us with the sound of a dog barking."

Despite Trump's rhetoric, his administration insists it is seeking a diplomatic resolution. Any military intervention designed to eliminate the North's nuclear and missile arsenal would almost surely entail dire risks for U.S. allies in the region, particularly South Korea, lying in range of the North's vast stockpiles of weaponry.

Fears of a military confrontation are increasing. North Korea conducted a series of provocative launches in recent months, including a pair of intercontinental missiles believed capable of striking the continental United States and another pair that soared over Japanese territory. It also exploded its most powerful nuclear bomb to date. Prodded by Washington, the U.N. has responded with the toughest economic sanctions on North Korea yet.

Still, the impasse is no closer to being resolved. Russia and China, which backed the new sanctions, want the U.S. to seek dialogue with the North. American officials say the time isn't right for any formal diplomatic process.

But other than using economic pressure to try to compel Pyongyang to give away its nuclear weapons - a strategy that has failed for the past decade - Trump's administration has yet to lay out a strategy for a possible negotiated settlement. In recent weeks, the administration's lack of direction has been all too apparent, as Trump and other top officials have vacillated between bellicose talk of possible military action and, at one point, even praise for Kim for a brief lull in missile tests.